Batteries

What Is a Hybrid Car Battery?

A hybrid car battery is like any other battery—except that it is rechargeable and has enough juice to move a large heavy vehicle down the road for a few feet or a few miles.

How Does It Work?

Like all batteries, hybrid batteries have two electrodes (which collect or emit an electric charge) that sit in an ion-rich solution called the electrolyte. (An ion, by the way, is an atom or group of atoms with an electrical charge.)

The electrodes are typically very close, so a polymer film, called a separator, prevents them from touching, which would create a short circuit. An on-off switch in whatever device is powered by the battery—your phone or laptop—bridges the cell’s electrodes to generate power. That’s when the electrochemical reaction begins.

Keep in mind: What we commonly call “a battery” is actually a battery pack that houses many individual cells. Your mobile phone battery is just one single cell, but anything larger—even a laptop battery—uses multiple cells working together.

Ionized elements in one electrode are in a chemical state where they are easily attracted to combine with other molecules, emitting electrons (energy) in the process. Those elements are tugged through the electrolyte and the separator toward the opposing electrode. The ions of the negative electrode (anode) give up electrons; the positive ions coming toward the anode accept them. The electrons released during this process travel through the external circuit (e.g. your phone), producing a flow of charge in the opposite direction to the flow of ions. During recharge, current is forced into the cell, reversing the process.

As we take a tour of hybrid batteries, remember one thing: Total energy determines the vehicle’s electric range, whereas available power determines its acceleration.